Much to the surprise of scientists, the cluster of dust and debris surrounding the young star HD 53143 appears highly elongated and complexly organised, with two rings and at least one planet.
A young sun-like star, HD 53143 is located about 60 light-years away in the southern constellation of Kiel. It was first observed in 2006 using the Hubble Space Telescope, which also saw a residual disk surrounding the star. Such discs appear in young systems, from debris and dust left over from the formation of planets and other large bodies. They are thought to be chaotic clusters of a more or less circular shape, similar to the Kuiper Belt at the distant periphery of the solar system.
But new observations from Chile's ALMA radio telescope have painted a very different picture. For the first time, astronomers have been able to see the remnant disk of the star HD 53143 in the millimetre wavelength range, which has turned out to have an unexpectedly elongated form and a complex internal structure. Meredith MacGregor (Meredith MacGregor) and her colleagues made the presentation at the 240th meeting of the American Astronomical Society (AAS). Their paper has been accepted for publication in the Astrophysical Journal Letters and is already available in the arXiv preprint library.
Instead of a rounded disk with a star at its centre, the scientists have seen an elongated oval with HD 53143 at one of its foci. Moreover, there appears to be another disk closer to the star, slightly rotated relative to the outer one. "For such a structure to form," says Meredith McGregor, "you need a planet, or several planets, whose gravity introduces perturbations to the motions of matter in the disk.
The structure surrounding HD 53143 has come as a big surprise to astronomers. Such disks help to understand how planets and planetary systems, including our own, are formed. "Residual discs are like fossils preserved from the time of planet formation," adds McGregor. - The new results show that there is still a wealth of unknowns to learn from them. This knowledge will enable us to understand the complex dynamics of young star systems similar to our own solar system."